I would be nice to know, wouldn't it?
If this is a true EPP system, then it will be up to the registrars to notify and contact registrants. It should have no change on the 30 day grace window, but likely would mean the end of registrar transfers for a suspended domain. Again, who knows?
One thing for you to consider would be 'registrant transferable' when a registration is suspended. EPP systems usually only permit changes to active domains, and even though the concept of a registrant transfer might be obsolete, simply changing the registrant with an EPP key would still likely require the domain to delivered to the new registrant as active.
As far as locking goes, every registrar has it. Whether they do it right is another thing.